First spoke of a hexagonal spiral.

Terms

a(0) =1a(1) =2a(2) =9a(3) =22a(4) =41a(5) =66a(6) =97a(7) =134a(8) =177a(9) =226a(10) =281a(11) =342a(12) =409a(13) =482a(14) =561a(15) =646a(16) =737a(17) =834a(18) =937a(19) =1046a(20) =1161a(21) =1282a(22) =1409a(23) =1542a(24) =1681a(25) =1826a(26) =1977a(27) =2134a(28) =2297a(29) =2466